Lumenair 9200psu

Contact the manufacturer. Curse them when they don't send you a schematic...

Most power supplies can be repaired without a schematic with some luck and careful observation. First step is look for vented electrolytics. Second step is to check all the big semis for shorts - Mosfets, diodes, etc. Third step is to ESR all electrolytics if not vented. Fourth step is to locate all ICs and get the datasheets for them (most available). The datasheets for the ICs will usually give a representative schematic that support the chips. Hopefully you don't need a step 5.

I often do a look listen and smell test. Look for burnt diodes or blown electrolytic caps. Listen for intermittence sounds when you tap components. Smell each component if it doesn't show a burnt circuit board below it.

You're sure about the brand name and model number?

If a supply is provided for a luminaire, it can react to failures in the lamps, which is much more common than psu failure.

RL

Thanks for all the help/advice. It's a psu controlling fish tank lighting (not mine, a friend asked me to look at it). The semi-conductors are all pretty obscure.

Chinese made, so not much chance of getting a circuit diagram off them I wouldn't think.

don't need a step 5.

I remember some blown selenium rectifiers that were impossible not to smell!

Your ident is either mis-spelled or mis-identified.

What kind of light? incandescent / fluorescent / LED ?

Are there voltage/current ratings on the label?

RL

That's the trade name on it.

I don't have access to what it controls, but as I said above it's something to do with fish tank lighting.

Yes, but what difference does that make?

However, I think I've located the problem - the first of them at least! There's a bridge rectifier that is not reading correctly, need to remove it to make more accurate checks.

You'll need a properly identified load, if only to duplicate failure symptoms and verify the repair.

What were the reported symptoms?

Does it flashes the load once, repeatedly or not at all, when power is applied?

Any smell associated with it?

Intermittent when line cord jiggled?

etc.

24V 10A is a pretty common rating, but the restriction for use with the specified load suggests that corners were cut in performance that may only be revealed by using that load in testing, unless you have a variable resistive/constant-voltage/ constant-current loads as substitutes.

RL